I submitted an app to Apple store, called rPlay, which does Chromecast emulation. The app is being reviewed right now. Here is the description:
"rPlay tunrs your iPhone/iPad/iPod into a chromecast device, so you can stream music and video from another device using chromecast enabled apps, such as YouTube and Google Music, etc. You can in turn stream from your iOS device to your Apple TV, this way, you can stream chromecast media to your Apple TV."
I hope Apple can approve this FREE app.
It supports YouTube/GoogleMusic/Custom Apps, chrome tab browsing is not there yet due to the lack of features in Safari browser.
This is a YouTube video:
Some screenshots are attached: